Clarian Labs, a Seattle-based tech startup that has been working on power source for the Department of Defense Humanoid Robot Program, has just pulled-out of stealth mode its rotary generator (read the patent here). A battery-sized hybrid generator solution, Clarian’s invention basically creates an electric power source that can be rapidly refueled by swapping out a fuel source pack (a host of fuels can be used in this regard including bio-fuels and hydrogen).

These fuels then in-turn power the rotary-piston motor, exactly as you’d find in any sort of Wankel-powered vehicle, except for one small detail: there’s no output shaft. Instead of mechanically driving the wheels of the vehicle, the unit uses rotational induction from the rotary-piston to create an electrical current, which would then power the electric motor of your choosing. In reality, the system isn’t that different from what is found on modern diesel locomotives (modern trains use a diesel motor as a generator which in-turn powers electric motors), except obviously more compact.

Realizing that battery technology is still a ways off from having the energy density, and perhaps more importantly the recharge time, necessary to be viable in an automotive application, Clarian’s approach is to use the benefits of existing fuels, and couple them with the advantages of electric output drives. With the energy density of hydrocarbon-based biofuels somewhere in the ballpark of 20-30 times more dense than current battery technology, there is still a considerable advantage for these fuels, even at a 30% energy conversion efficiency in modern drivetrains. Add on top of this a refuel time that’s comparable to current ICE engines, and there’s some weight to this idea of engines as generators.

What makes Clarian’s rotary generator extra unique is that the motion of the rotor assembly is not constant, and can be adjusted on the fly to produce more power, optimize fuel consumption, control vibration, and to limit peak loads. For even more adjustability and modularity, the generator can have several rotary pistons, but unlike in a car, they are not mated to a common crankshaft. This means that pistons can be activated and deactivated according to application demands, e.g. turning on an extra piston to create more power to race up a hill, or pull a heavier load.

Clarian wants us to think of its rotary generator as a “powerful self-contained electromechanical battery”, which is sort of a misnomer, since batteries store energy. However since the whole package can be self-contained, the form factor is certainly battery-sized. According to Clarian, the use of a rotary generator also means that the company’s solution has twice the power-to-weight ratio of traditional piston generators. What really tickles our fancy with this unit, is that if you ran the rotary generator off of hydrogen fuel, it would technically be race legal in any of the zer0-carbon race series currently running. Chewy, thanks for the tip Mike!

What am I missing here? This is, except for possibly the add-a-piston concept (cylinder deactivation, anyone?), a generator. Nothing more, nothing less. There are dozens of old and new generator designs around. So many concepts, in fact, that I wrote an article about it: http://www.greentechmedia.com/articles/read/guest-post-whats-the-best-ev/. Rotaries are good, no doubt; but so are other designs. Still, I do really believe in range extenders, so I wish them good luck. (As to running hydrogen, huge freakin’ ha! Within reasonable design limits, any internal combustion engine can run on hydrogen — but hydrogen does not make the process magically “clean” unless the hydrogen came from renewable energy-powered electrolysis, and if that’s the case it’s far better to simply use the electricity in the first place and not use two processes to convert the electricity to hydrogen and back to electricity while losing about 70% of your electrical energy in the process).

GeddyT

I also don’t get it. Although Wankels do beat piston engines in power to size and, to a much smaller degree, power to weight, aren’t they also currently far less fuel efficient? All I see this design doing is eliminating the mechanical linkage between engine and generator. Is this really enough of an efficiency gain to offset the efficiency gap between a piston and Wankel engine? I’d think it’s at best a wash, but I’d like to see the numbers.

http://www.bikewriter.com Mark Gardiner

Tres elegant little gadget.

But, uh, ‘Humanoid Robot’?!? Talk about another Defense Dept. boondoggle. I mean sure, on the face of it it seems like a good idea to build robots you can send into combat zones, so that real people aren’t put into harm’s way. But the overwhelmingly white, urban- and suburban-dwelling readers of A&R should have already realized that despite the tens of thousands of casualties suffered in Irate and Afghastlystan, they don’t personally know or even see any killed or wounded vets. IE, there already is a program to send in proxy war-fighters — it’s called recruiting the poor, the black and latino, and rural-dwellers. We don’t need robots, we need an unbiased draft. In short order war zone casualties will plummet.

http://www.asphaltandrubber.com Jensen Beeler

But Mark, talking about humanoid battlebots makes us feel better about the social elite class structure Duh!

Steve R

First thing I thought of upon seeing the image was: I hope that is going in a motorbike!

“Realizing that battery technology is still a ways off from having the energy density, and perhaps more importantly the recharge time, …”

I agree on the density issue, but for applications where budget is not an issue (military, racing, etc.) a battery swap is as quick as a refuel. OK, maybe not all refueling types. I have a hard time imagining doing a battery swap on an inflight fighter jet! But for humanoid robots, it should be no problem!

W

@Mark Gardiner, first off I am not a Hawk, no desire for war, and no desire to go myself.

I get what you are trying to say but your argument is not valid as long as joining the military is a personal choice, that those who join make. That choice is made for a number of reasons from a strong family history of service, to the simple patriotic desire to serve, to the promise of a college education, to the feeling that service might the only possible path to a better life, to a lack of another life plan. To categorically call our service members proxy fighters, inferring that somehow they are not capable of making a decision not to go is to discount that many valid reasons that the members of our military justify their choice to serve and it does them an incredible injustice.

As to you suggestion of an unbiased draft, I agree (easy for me as someone who’s parents served but who has never had to face a draft). I do believe that mandatory military service combined with unsanitized war reporting (as you see in Europe) would reduce the desire in our country for any war.

For now, if someone doesn’t want to join the military, they don’t have to. It really is that simple. Don’t make excuses for those who join, they don’t need them.

Westward

@ W

Ones social-econimical environment dictates reality. There are areas in the US, where for some, the military seems like the only option for economic survival. Just like coal mining in certain areas West Virginia, or like fishing in a lot places of the world… No too long ago I watched a documentary, where the only means of financial support was shovelling piles of salt in the middle of nowhere, and they went to work on bicycles…

Though I think I know where you are coming from, my father and his father served, I also understand what Mark is articulating. You are both right, and it’s not easy to generalise, as there is no black or white, but many shades of grey in between as well…

As for the subject at hand, I really hope this helps to advance new technology in motorcycles. What we need is more, out of the box thinking like this before we hit the jackpot… I can’t wait for the day, when petrol is just another option to a couple of other different fuels on the market, like selecting a candy bar in the grocery checkout line…

Fearnow

Cripes! When did ‘reading the comments’ start to not suck?

Good comments and reasonable responses….is there hope for this world yet? :)